1. Field of the Invention
This invention relates to a system and a method for semiconductor processing process control, and more particularly, to a semiconductor processing process control system capable of flexibly, quickly coping with changes in processing process, method of computing control variables and processing equipment, and its control method.
2. Description of the Related Background Art
For manufacturing semiconductor devices such as IC, LSI, and so on, they undergo many processes like etching, cleansing, inspection, and others, and intended processing is conducted in each process. For realizing intended processing, control conditions each processing apparatus and its processing time must be adjusted appropriately.
For example, in case of stacking a film in a certain process, material of the film (film material) and its thickness are targets of the processing. The content of this processing is to make a film of an intended material on a specific semiconductor. Only when control conditions of the deposition apparatus (in case of a CVD apparatus, the are conditions on the material of the gas, flow rate of the gas, temperature, etc.) are selected properly, the intended content of the processing (making a film of an intended material) can be realized, and the film thickness can be controlled by adjusting the duration of time of the deposition (deposition time). The deposition time can be obtained by dividing the target film thickness by the deposition rate (film thickness stacked in a unit time, namely, a kind of processing speed). Such deposition rates are previously measured upon maintenance of the apparatus, for example, and held in form of a rate table.
When etching processing is conducted, the content of the processing is to etch a film of a specific material stacked on a specific semiconductor, and this processing content and the etching depth (film thickness) are the target of the processing. To realize this content of the processing, control conditions of an etching apparatus are determined. Further, the etching time (processing time) is determined by dividing the target etching depth (thickness) by the etching rate (etching depth in each unit time, i.e., a kind of processing speed). Such etching rates are held as a rate table similarly to the case of deposition of films.
To supervise control conditions of processing apparatuses and processing times in a plurality of processes, a semiconductor processing process control system is used. Taking here deposition of a film (as a single process) as an example of processing content, a flow of process control by a conventional semiconductor processing process control system is shown. The process flow is shown in FIG. 29, and the flow of process control is shown in FIG. 30.
As shown in FIG. 30, a semiconductor processing process control system CS1 reads out the processing target (in this case, material and thickness of the film to be stacked) of the process and control conditions of a processing apparatus from process flow information IF1. Then, the semiconductor processing process control system CS1 obtains the processing time (in this case, deposition time) by referring to a rate table RT1 and dividing the target film thickness by the deposition rate. In this example, 100 minutes obtained by dividing 1000 angstrom as the target film thickness by 10 angstrom/min. as the deposition rate is the deposition time. Then, it sends the control variables (setting of conditions concerning control of the processing apparatus involving both control conditions of the processing apparatus and its processing time, also in the description made hereunder) to the processing apparatus PA1 like a deposition apparatus or its control device, for example. In the example shown in FIG. 30, the control method for the target process is a fixed method.
FIGS. 31 and 32 show method of computing the processing time upon stacking a plurality of films and the processing time upon etching a plurality of films. In this case, since control conditions and processing speed (deposition rate, etching rate, etc.) of the processing apparatus PA1 vary with materials of films to be stacked or etched, processing time must be calculated for each step for processing each film.
The semiconductor processing process control system CS1 may be made up of hardware alone. Normally, however, it can be made as programs on a computer (software) to ensure quick response to changes in process, etc. This is shown in FIG. 33.
As shown in FIG. 33, there are process control programs CPG for respective processing apparatuses PA1 through PA4 used for respective processes, and these programs control the processing apparatuses PA1 through PA4. That is, a set of a plurality of process control programs CPG realizes the function of the semiconductor processing process control system CS1. When the process and the apparatus therefor are changed from one to another, the system can copes with it by changing the content of the respective process control programs CPG.
However, there is the problem that control conditions are not fixed ones determined only by processing apparatuses PA1 through PA4 and processing contents and deposition rate is not always constant.
That is, control conditions are variable with the history of use of each processing apparatus. Additionally, deposition rate may change depending on the status of the base on which a target film should be stacked. Therefore, it is possible that the deposition rate varies with thickness of the stacked film.
As a method dealing with this problem, Japanese Patent Laid-Open Publication No. hei 8-45804 discloses a method for computing appropriate control conditions taking the past control conditions into consideration, and Japanese Patent Laid-Open Publication No. hei 6-196404 discloses a method for computing a processing time from a target film thickness.
These methods for computing control conditions and processing time are not always fixed but may vary with target processing contents and other factors. Conventional semiconductor processing process control systems, however, could not flexibly cope with changes in calculation method of control conditions and processing time, and were compelled to re-make the whole program every time upon changing the calculation method.
Furthermore, conventional systems involved the problem that they needed a change of the whole program also upon every change of the processing apparatus and process (not only a change of the process from one to another, but also omission and addition of a step).
As explained above, conventional semiconductor processing process control systems could not quickly cope with changes in process, calculation method of control variables, processing apparatus, and so on, and as a result, there was the possibility of delaying development of semiconductor devices.
It is therefore an object of the invention to provide a semiconductor processing process control system which can flexibly, quickly cope with changes in process, calculation method of control variables and processing apparatus.
In order to accomplish the aforementioned and other objects, according to one aspect of the present invention, a semiconductor processing process control system comprises:
a process controller main body having a function of controlling part of controls of processes for semiconductor processing, which is independent from semiconductor processing devices and processing targets; and
a plurality of control variable computing sections provided for respective the semiconductor processing devices and the processing targets, and detachably inserted into to the process controller main body to obtain control variables of semiconductor processing devices which meet the semiconductor processing devices and the processing targets, the process controller main body controlling processes of semiconductor processing on the basis of the control variables obtained by the control variable computing section inserted therein.
According to another aspect of the present invention, a semiconductor processing process control system comprises:
a process controller main body having a function of controlling part of controls of processes for semiconductor processing, which is independent from semiconductor processing devices and processing targets;
a plurality of control variable computing sections provided for respective the semiconductor processing devices and the processing targets to obtain control variables of semiconductor processing devices which meet the semiconductor processing devices and the processing targets; and
a control variable computation method section detachably inserted into the process controller main body to manage the control variable computing sections according to a computing method over a plurality of predetermined processes, the control variable computing sections detachably inserted into the control variable computation method section, the process controller main body controlling processes of semiconductor processing on the basis of the control variables obtained by the control variable computation method section inserted into the process controller main body and the control variable computing section inserted into the control variable computation method section.
According to a further aspect of the present invention, a semiconductor processing process control system for controlling a plurality of processes for semiconductor processing, comprises:
a skip judgment request receiving section which receives a request for judgment whether a process can be skipped or not;
a plurality of judgment plug-in each having a step skip judgment logic for judging whether a certain process can be skipped or not;
a skip judgment yes/no section for searching out a judgment plug-in corresponding to a process to be judged, which is received by the skip judgment request receiving section, from the plurality of judgment plug-in;
a judgment execute section which activates the judgment plug-in searched out by the skip judgment yes/no section and makes the judgment plug-in judge whether the one process can be skipped or not, on the basis of the step skip judgment logic;
a judgment result receiving section which receives from the activated judgment plug-in a result of judgment whether the one process can be skipped or not; and
a skip execute section which effects skipping of the one process when the result of judgment indicates that the process can be skipped.
According to one aspect of the invention, a method for controlling a semiconductor processing process control system which includes a process controller main body having the function of controlling part of controls of processes for semiconductor processing, which is independent from semiconductor processing devices and processing targets, comprises the steps of:
selecting one of a plurality of control variable computing sections which are provided for respective the semiconductor processing devices and the processing targets and can be detachably inserted into the process controller main body, and inserting the control variable computing section, which is selected, into the process controller main body;
operating the control variable computing section inserted into the process controller main body to obtain a control variable of a semiconductor processing device, which is agreeable with the semiconductor processing devices and the processing targets; and
operating the process controller main body to control a process for semiconductor processing on the basis of the control variable obtained.
According to another aspect of the invention, a method for controlling a semiconductor processing process control system which includes a process controller main body having the function of controlling part of controls of processes for semiconductor processing, which is independent from semiconductor processing devices and processing targets, comprises the steps of:
selecting at least one of a plurality of control variable computing sections, which are provided for respective the semiconductor processing devices and the processing targets;
selecting one of a plurality control variable computation method sections which manage the control variable computing sections over a plurality of processes, the control variable computation method sections being configured to be detachably inserted into the process controller main body when necessary, and the control variable computing sections being configured to be detachably inserted into the control variable computation method sections;
inserting the control variable computing sections selected into the control variable computation method section selected, and inserting the control variable computation method section into the process controller main body;
operating the control variable computation method section inserted into the process controller main body and the control variable computing section inserted into the control variable computation method section to obtain a control variable of a semiconductor processing device which is agreeable with the semiconductor processing devices and the processing targets; and
operating the process controller main body to control processes for semiconductor processing on the basis of the control variable obtained.
According to a further aspect of the invention, a method for controlling a semiconductor processing process control system configured to control a plurality of processes for semiconductor processing, comprises:
a skip judgment request receiving step for receiving a request for judgment whether a process can be skipped or not;
a search step for searching out a judgment plug-in corresponding to a process to be judged, which is received by the skip judgment request received in the skip judgment request receiving step from a plurality of judgment plug-in, each the judgment plug-in having a step skip judgment logic for judging whether a certain process can be skipped or not;
a judgment execute step for activating the judgment plug-in searched out to judge whether the one process can be skipped or not;
a judgment result receiving step for receiving from the activated judgment plug-in a result of judgment whether the one process can be skipped or not; and
a skip execute step which effects skipping of the one step when the result of judgment indicates that the process can be skipped.